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The influence of the platelet-activating factor receptor-antagonist (BN 52021) and polyelectrolyte solution (PES) on the morphology and oxidant-antioxidant equilibrium in the gastrointestinal wall in hemorrhagic shock was examined in rats. The animals were divided into five groups: I - control, II - sham operation, III - untreated hemorrhagic shock lasting 75 minutes, IV - shock treated with PES, and V - shock treated with BN 52021 and PES. The most expressed morphological changes were found in the small intestine in group IV (shock treated with PES) and in group III (untreated shock). Morphological changes were well correlated with the malondialdehyde (MDA) level reflecting oxidative tissue injury and with the antioxidative potential: sulfhydryl compounds (-SH) level, and superoxide dismutase (SOD) activity. The signs of morphological and biochemical injury to the gastrointestinal tract in animals from group V (treated with BN 52021 and PES) were significantly less expressed than those in groups III and IV. The results suggest an essential role of PAF in oxygen radicals-mediated gastrointestinal injury and a beneficial effect of the early application of BN 52021 in hemorrhagic shock.

The number and morphological types of megakaryocytes (MK) in the rat inferior cava vein blood were evaluated in untreated hemorrhagic shock lasting 60 min and in 6 to 48 hours after treatment with a standard polyelectrolyte solution (PES). The rats were bled through carotid artery. MK were isolated using the 5 microns filters. The results were compared with those found in the control animals not subjected to surgical manipulation and subjected to sham operation (cervical incision only, and cervical incision + carotid artery cannulation). The most considerable increase in the circulating MK occurred in 12 hours after the PES treatment. The slight increase in the number of MK was also observed in rats with carotid artery cannulation without hemorrhage. Increase in the MK number was accompanied by a shift in their morphological types.